Place flour on a surface and create a central well.
Mix 250g butter and salt into the flour until grainy, then work in water to form a marbled dough.
Roll dough into a ball, wrap, and refrigerate for 20 minutes.
Roll pastry into a 40x20cm rectangle, fold into thirds, turn, repeat, and chill for 30 minutes.
Perform two more rolling and folding turns, then chill for at least 30 minutes.
Preheat oven to 200°C.
Melt caster sugar in blini pans until golden-brown, then stir in the remaining butter and a pineapple ring.
Cut two pastry circles larger than the pans and tuck them over the pineapple.
Bake for 10-12 minutes until golden brown.
Simmer butter, brown sugar, and syrup in a pan until dissolved.
Remove sauce from heat and stir in lemon juice, cream, and coconut liqueur.
Toast flaked coconut in a dry pan for 2 minutes.
Serve tart slices with ice cream, sauce, toasted coconut, and mint.